10 research outputs found
Utvrđivanje raspona dobi i reproduktivne aktivnosti smeđih medvjedica (Ursus arctos) iz zatočeništva pomoću morfohistološke pretrage jajnika - kratko priopćenje
The study aimed to determine reproductive span by investigation of the ovarian structures in young and elderly captive brown bear females (Ursus arctos). The ovaries of two 2-year-old females were obtained by ovariectomy and during the necropsies of 31 and 36 year old individuals. All the obtained ovaries were examined macroscopically and histologically. Histological examination of the ovaries of young animals (2+ years) revealed the presence of primordial, primary, secondary and tertiary follicles within the ovarian cortex. One ovary showed a mature corpus luteum, indicating recent ovulation, what is, to our knowledge, the first histological proof of the earliest age of ovulation recorded for captive brown bears. Ovarian atrophy accompanied by the development of multiple cystic subsurface epithelial structures (SES) in the case of the old bears in this study indicates that the ovaries of brown bears share similar degenerative and proliferative patterns with domestic canids. The oldest female had records of successful births at the ages of 26 and 28 years. Both recorded birth events represent one of the latest confirmed occurrences of ovulation, conception and birth amongst brown bears.Cilj istraživanja bio je pregledom građe jajnika utvrditi raspon dobi i reproduktivne aktivnosti u mladih i starih ženki smeđega medvjeda (Ursus arctos) iz zatočeništva. Jajnici su dobiveni ovariektomijom dviju dvogodišnjih ženki i tijekom razudbe 31-godišnje te 36-godišnje ženke. Svi su jajnici pregledani makroskopski i histološki. Histološkom pretragom u mladih su životinja u kori jajnika otkriveni primordijalni, primarni, sekundarni i tercijarni folikuli. U jednom je jajniku dokazano zrelo žuto tijelo (corpus luteum), pokazatelj nedavne ovulacije što je, prema nama dostupnim podacima, prvi zabilježen histološki dokaz najranije ovulacije u smeđih medvjeda u zatočeništvu. Atrofija jajnika povezana sa starenjem i praćena razvojem multiplih cističnih supseroznih epitelnih struktura (SES) u starih medvjeda u ovom istraživanju upućuje na to da se u smeđih medvjeda pojavljuju slične degenerativne i proliferativne promjene kao i u domaćih kanida. Najstarija ženka imala je zabilježene uspješne porođaje u dobi od 26 i 28 godina. Oba porođaja pripadaju najkasnijim potvrđenim pojavama uspješne ovulacije, začeća i porođaja u smeđih medvjeda
Metal(loid) exposure assessment and biomarker responses in captive and free-ranging European brown bear (Ursus arctos)
We investigated the level of five non-essential metal(loid)s (As, Cd, Hg, Tl, Pb) and nine essential metals (Mg, Ca, Mn, Fe, Co, Cu, Zn, Se, Mo) in hair and blood components of captive and free-ranging European brown bear populations in Croatia and Poland. Metal(loid) associations with biomarkers of oxidative stress (superoxide dismutase, SOD ; glutathione- peroxidase, GSH-Px ; malondialdehyde, MDA) and metal exposure (metallothionein, MT) were estimated in this top predatory mammal. Lead was the most abundant non-essential metal(loid) in both blood and hair, with 4 of 35 individuals having blood levels over 100 µg/L. A positive association was found between Pb level and SOD activity in blood. Free-ranging bears had higher blood SOD activity, Mn, Zn and Cd levels, hair Co, Cd, Tl and Pb compared to captive individuals, while the opposite was true for Mg and hair Ca thereby reflecting habitat and diet differences. With increasing age, animals showed lower levels of SOD activity and certain essential metals. Females had higher SOD activity and blood levels of some essential metals than males. Hair showed a higher Fe and Co level when sampled during the growth phase and was not predictive of non- essential metal(loid) blood levels. The established metal(loid) baseline values will enable future risk assessment in both captive and wild European brown bear populations
A microsatellite study in the Łęgucki Młyn/Popielno hybrid zone reveals no genetic differentiation between two chromosome races of the common shrew (Sorex araneus)
This study investigated a chromosome hybrid zone between two chromosomal races of the common shrew (Sorex araneus). Gene flow and genetic structure of the hybrid zone, located in the northeast of Poland, were studied using seven polymorphic autosomal microsatellite loci (L9, L14, L33, L45, L67, L68, L97) and a Y-linked microsatellite locus (L8Y). Seventy-five animals (46 of the Łęgucki Młyn race and 29 of the Popielno race) from nine different localities were examined and the data were analyzed using hierarchical AMOVA and F-statistic. The studied microsatellite loci and races (divided into nine geographical populations) were characterized by observed heterozygosity (HO), expected heterozygosities within (HS), and between (HT) populations, inbreeding coefficient (FIS), fixation index (FST), and average allelic richness (A). We found that genetic structuring within and between the two chromosome races were weak and non-significant. This finding and unconstrained gene flow between the races indicates a high level of migration within the Łęgucki Młyn/Popielno hybrid zone, suggesting that evolutionarily important genetic structuring does not occur in interracial zones where races which are not genetically distinct come into contact
Genetic differentiation of the sand lizard populations, Lacerta agilis Linnaeus, 1758 (Reptilia, Lacertidae) in central Europe
International audienceEight populations of the sand lizard (Lacerta agilis) from Poland (allozymes and cytochrome b gene sequences) and 18 populations from Poland, Slovakia, Austria, Hungary, Croatia, Italy, France and Russia (dloop region sequence) were studied. The level of allozyme polymorphism is very low. It was only found in two loci of two enzyme systems (MOD and PGD) among the 8 loci studied and only in two populations from North-Eastern and Central-Eastern Poland. Bayesian Inference and additional phylogenetic analyses basing on cytochrome b gene and dloop region indicate clearly that haplotypes from these two populations form a separate clade. The study confirms the homogenity of sand lizard populations in Central Europe (L. agilis argus) except for populations from NE and E of Poland (L. agilis chersonensis). Dloop analysis suggests the position of sand lizard from Croatia as L. agilis bosnica
Genetic differentiation of the sand lizard populations, Lacerta agilis Linnaeus, 1758 (Reptilia, Lacertidae) in central Europe
International audienceEight populations of the sand lizard (Lacerta agilis) from Poland (allozymes and cytochrome b gene sequences) and 18 populations from Poland, Slovakia, Austria, Hungary, Croatia, Italy, France and Russia (dloop region sequence) were studied. The level of allozyme polymorphism is very low. It was only found in two loci of two enzyme systems (MOD and PGD) among the 8 loci studied and only in two populations from North-Eastern and Central-Eastern Poland. Bayesian Inference and additional phylogenetic analyses basing on cytochrome b gene and dloop region indicate clearly that haplotypes from these two populations form a separate clade. The study confirms the homogenity of sand lizard populations in Central Europe (L. agilis argus) except for populations from NE and E of Poland (L. agilis chersonensis). Dloop analysis suggests the position of sand lizard from Croatia as L. agilis bosnica
Genetic differentiation of the sand lizard populations, Lacerta agilis Linnaeus, 1758 (Reptilia, Lacertidae) in central Europe
International audienceEight populations of the sand lizard (Lacerta agilis) from Poland (allozymes and cytochrome b gene sequences) and 18 populations from Poland, Slovakia, Austria, Hungary, Croatia, Italy, France and Russia (dloop region sequence) were studied. The level of allozyme polymorphism is very low. It was only found in two loci of two enzyme systems (MOD and PGD) among the 8 loci studied and only in two populations from North-Eastern and Central-Eastern Poland. Bayesian Inference and additional phylogenetic analyses basing on cytochrome b gene and dloop region indicate clearly that haplotypes from these two populations form a separate clade. The study confirms the homogenity of sand lizard populations in Central Europe (L. agilis argus) except for populations from NE and E of Poland (L. agilis chersonensis). Dloop analysis suggests the position of sand lizard from Croatia as L. agilis bosnica
Histological, chemical and behavioural evidence of pedal communication in brown bears
Most mammals rely upon scent for intraspecific communication. As most bear species have large home
ranges and are non-territorial, scent deposit while walking could be an effective way to communicate
with conspecifics. Here, we investigate the existence of pedal glands in brown bears and their
role in chemical communication from a histological, biochemical and behavioural perspective. We
found eccrine glands in footpads, and prominent apocrine and sebaceous glands in the interdigital,
metacarpal and metatarsal skin sections. Pedal scent contained 26 compounds including carboxylic
acids, important constituents of mammalian secretions. Six of these compounds were exclusive for
males. Finally, we describe a specific marking gait recorded in the field, mostly performed by males. Our
study supports the existence of chemical communication through pedal marking in brown bears and
suggests sex-coding potential of pedal scent.Peer reviewe